Circuitry consisting of resistive, inductive, and capacitive elements (RLC circuits) has long been used to attenuate transient noise in direct current electrical circuits. However, it has not always been possible to successfully employ RLC circuits to attenuate noise alternating current circuits, due to the high rate of change of voltage with respect to time inherent in alternating current circuits. For example, in a 165 volt root-mean-square (rms) 8,000 hertz application, it was found difficult to attenuate noise having a frequency above one-hundred mega-hertz.
Therefore a need exists for noise attenuation circuitry that will protect sensitive integrated circuit components from being damaged by transient high-frequency noise generated by electro-mechanical relays.